Polarity-indicator.



PATENTED 00T. 24, 1905.

F. W.AMANGER & C. E. AVERY.

POLARITY INDICATOR.

AeyPPLIoATIoN FILEB MA1124., 1904. www

ATTORNEY l ED STATES lr-YTENT @Ell FREDERICK W. MANGER AND CHARLES E.AVERY, OF JERSEY CITY, N EIN JERSEY, ASSIGNORS TO MANHATTAN ELECTRICALSUPPLY COMPANY, A CORPORATICN OF NEW JERSEY.

POLARlTY-INDICATOR.

Specification of Letters Patent.

Patented Oct. 24, 1905.

Application filed March 24, 1904. Serial No. 199,886.

To LM w/wm/ t may concern:

Be it known that we, FREDERICK IV. MAN- GER and CHARLES E. AVERY,citizens of the United States, and residents of the city of Jersey City,Hudson county, New Jersey, have invented certain new and usefulImprovements in Polarity-Indicators, of which the following is a full,clear, and eXact description, reference being had to thev accompanyingdrawings, forming a part of this specification.

The object of this invention is to provide a simple, compact, anddurable instrument, which may be conveniently carried in the pocket, bywhich the direction of the current flowing through an electric circuitmay be readily determined.

A practical embodiment of our invention in a preferred form isillustrated in the accompanying' drawings, in which- Figure 1 is aslightly-enlarged external View of the instrument. Fig. 2 is a centrallongitudinal section, and Fig. 3 is a transverse section, on -the line 33, Fig. 2.

Similar reference characters are employed to designate like parts in allthe views.

The instrument in the form illustrated comprises a herinetically-closedglass tube A, provided with two electrodes B and C, one at each end. Theelectrodes are usually made of platinum and are sealed into the ends ofthe tube, so as to project well into the tube and eX- tend slightlybeyond the ends thereof. The tube A is lilled with a suitable liquid orchemical solution, which is decomposed and becomes diseolored at thenegative pole by the passage of electric current through the liquid, andrecoinbines, assuming its normal color when the currrent ceases to liow,this property of certain chemical solutions being well understood bythose skilled in the art to which our invention pertains. The tube A isinclosed in a i case preferably constructed of hard rubber,

and in the form shown comprises the central cylindrical portion D andthe removable ends or caps E and F. The ends of the cylindrical portionof the case are eXteriorly screwthreaded and the caps arecorrespondingly threaded to screw over them. The central portion of thecase D is provided with an opening G, through which the action of thecurrent on the contained liquid may be observed. The caps E and F are ofslightlygreater diameter than the body D of the case, and between theprojecting ends of the caps is inclosed a revoluble cylinder or shieldH, which is provided with a sight-openingl, correspending with theopening' in the case D. By rotating the shield H, which is usually madeof stili metal to carry the opening I past the opening Cr in the case,the tube A will be protected against breakage. To prevent a too freemovement of the shield, a helical spring J is mounted in a recess in thecase to bear against the inner surface of the shield, thus creatingsuflicient friction between the shield and the case to retard therotatory movement of the shield.

Binding-posts K and L or other suitable contacts are carried by the capsE and F. To insure a perfect contact between the inner ends of thebinding-posts and the electrodes, we interpose between the post L andthe tube a small mass of tin or other conducting metal foil M. At theopposite end of the instrument we employ similar foil contacts, onecontacting with the post K and the other with the electrode B, andinterpose between them a conducting-spring N. This serves to hold thecontacts firmly together, while the spring will yield sufliciently toprevent the breaking of the tube by any end wise pressure prod uced bythe screwing on of the caps.

To prevent the tube A from turning in the case D, we provide a smallprojection t on the side of the tube at one end and form a slot d in theinterior surface of the tube into which the projection a/ extends. Thisproliection t may be conveniently formed in closing the iilling-openingof the tube A.

If the terminals of an electric circuit or the adjacent ends of acurrent-carrying conductor be connected to the binding-posts K and L,the liquid in the tube immediately adjacent to the negative pole will bediscolorcd, and the direction of the current can be instantlydetermined.

Modifications in the form and arrangement of the parts of the particularform of instrument which We have herein shown and described will suggestthemselves to those skilled in the art, and allsuch as may be madewit-hout departing from the spirit of our invention we intend to coverby the appended claims.

Having` thus shown and described our invention, what we claim as new,and desire to secure by Letters Patent, is-

1. In a polarity-indicator, the combination of a transparent tubehermetieally closed and Containingl a suitable liquid, an electrodesealed in each end of the tube, an inelosing case for the tube providedwith a sight-opening, removable ends for the case, contacts carried bythe ends of the case and metallic connections between the contacts andelectrodes.

2. In a polarity-indicator, the combination of a transparent tubehermetically closed and containing' a suitable liquid, an electrodesealed in each end of the tube, an inelosing ease for the tube providedwith a sight-opening, screw-caps forming ends for the case, Contactscarried by the caps and metallic Connections between the Contacts andelectrodes.

3. In a polarity-indicator, the Combination of a transparent tubehermetieally closed and Containing` a suitable liquid, an electrodesealed in each end of the tube, an inelosing case for the tube providedwith a sight-opening, screw-caps forming ends for the ease, Contactscarried by the caps and yielding metallic connections between thecontacts and electrodes.

the electrodes, and a revoluble shield for the sight-opening` in theease.

5. In a polarity-indicator the Combination of a transparent tubehermetieally sealed, an electrode sealed in each end of the tube, aninelosing ease provided with a sight-opening, caps of greater diameterthan the case secured thereto, a revoluble shield for the sight-openingfitted between the projecting caps, and contacts carried by the caps inmetallic oonneetion with the electrodes.

6. In a polarity-indicator, the Combination with a transparent tubecontaining a suitable liquid and carrying an electrode at each end, aease for the tube, ends for the ease, and a conducting-spring arrangedbetween one end of the tube and the end of the oase to exert a yielding'pressure on the tube.

FREDERICK W. MANGER. CHARLES E. AVERY. Witnesses:

E. M. TAssERY, O. H. HUEBEL.

